Proliant 1600 won't boot; power supply/backplane problem?

[BH_2]

It all started when I installed a tape drive. I removed some cables to get the drive in. The problem is, I'm not 100% that I am trying to reconnect the proper cable. I saw another post referencing the same issue that I am having. A cable labeled "P5" was mentioned which is supposedly used to connect to the backplane (just to the right of the bottom SCSI connector. However, I don't see the P5 cable. The one I am thinking I should use is labeled C2. It is a black rectangular cable with 7 rows of slots (14 total, 1 being keyed). The wires are all black except one that is red. Does this sound like the right cable? Can someone describe the looks of the P5 cable? Also, does it come from the power supply below?
It appears as though everything is getting power except my CPU's. However, the fan on the CPU tray is getting power. I can also see an LED that lights up on the board. Although the HDD's light up for a split second after the server is powered on, there is no activity after. I am also not getting any video output. I had tried re-seating just about every card and cable. I've also tried booting without the RAM to no avail (should still get video output and error beep). I have also tried installing a new PCI video card to eliminate the on-board video as an issue. My biggest concern is restoring the data on the drives. Although I'd rather get the server booted up and functional again, I'd settle for taking the drives out, restoring the data (somehow), and scrapping the server. Can anyone please help?
Thanks!

-BH

[JohnWRuffo]

When reconnecting the cables from the power supply to the backplane board, match cables P1, P2, and P5 with the appropriate connectors.
Cable P5 should plug into the far left side of connector P5. The attached .gif depicts the positions of these cable connectors on the backplane board.

Here is a link to the ProLaint 1600 Maintenance and Service Guide:
http://h200002.www2.hp.com/bc/docs/support/UCR/SupportManual/TPM_179480-001_rev3_us/TPM_179480-001_rev3_us.pdf